L2_remove_head
void *L2_remove_head(L2el_t *headp);
if ((gcmdp = L2_remove_head(&GDEV_QHEAD(gdevp))) == NULL) {
gcmdp = (gcmd_t *)L2_remove_head(&GHBA_QHEAD(cccp));
void *L2_remove_head(L2el_t *headp);